The present invention relates to an endoscope apparatus and, more particularly, to an endoscope apparatus comprising an air-/liquid-supply device.
When a body cavity is examined, using an endoscope, an insertion section of the endoscope is inserted into the body cavity. Upon insertion, filth, mucus, and the like tend to become attached to an observation window incorporated in the insertion section. In this case, a portion of interest cannot be properly observed. Therefore, the observation window is usually cleaned by using an air-/liquid-supply device, thereby removing the filth, mucus, and the like attached to it.
In general, an endoscope comprises a spray nozzle arranged on the insertion section and directed toward an observation window, and air- and liquid-supply pipes communicating with this nozzle. The air-/liquid-supply device comprises a liquid storage tank, connected to the air- and liquid-supply pipes, for storing a liquid, and an air pump connected to the tank. When the observation window is to be cleaned, the liquid in the liquid storage tank is compressed by way of the air pump, is fed into the liquid-supply pipe, and sprayed out of the nozzle, onto the observation window, to thereby remove filth attached thereto. After this, the compressed air from the air pump is blown out of the nozzle, through the air-supply pipe, so as to remove the liquid clinging to the observation window.
However, following the above cleaning process, waterdrops sometimes remain on the observation window. When this occurs, it is difficult to perform a proper diagnosis and carry out the appropriate medical treatment, because the field of observation is partially obscured by the waterdrops. Thus, when a region of interest is to be treated by using the RF treatment device, a laser treatment device, or the like, a region other than the actual region of interest may be erroneously damaged.
Therefore, techniques have been proposed for reliably removing waterdrops remaining on the observation window, by means of blowing high-pressure air from the nozzle. For example, an apparatus having a high-pressure air supply means connected to an intermediate portion of an air-supply pipe of an endoscope or to a liquid storage tank is disclosed in Japanese Utility Model Disclosure (Kokai) No. 59-64101.
However, when the air-supply means is arranged in the operation section of an endoscope, and connected to the air-supply pipe, the weight of the operation section increases considerably, thus degrading the operability of the endoscope. When the air-supply means is connected to an air tank, there is a significant time delay before high-pressure air is blown from the nozzle, after the air-supply means has been activated.